Numerical calculations of turbulent recirculating heat transfer beyond two-dimensional back-steps and sudden pipe expansions

Extensive results of numerical calculations for turbulent recirculating flow with heat transfer are presented. The geometries studied were two dimensional flows over rearward (backward)--facing steps and sudden pipe expansions. The computations described were performed using the k-epsilon, two equation model of turbulence. To yield better predictions of heat transfer, the standard model was improved, by developing algebraic approximations for Reynolds stresses and scalar fluxes, so as to account for the effects of streamline curvature, pressure-strain and variation of turbulent Prandtl number in the flow field. In addition, the low-Reynolds-number version of the standard k-epsilon model was employed in the redeveloping region. In order to apply the low-Reynolds-number model to the redeveloping region, a two pass procedure was developed to partition the flow field into separated and reattached regions.